meaning - can I use "used to" for something is "used for" some objective?

I am curious about using "used to" which is used for expressing some habitual actions in the past. But how to use it for passive voices?

Example 1:

I used to eat chocolate too much when I was a baby

This example is OK. What about the second one?

Example 2:

a) This computer is used to calculate statistics.

b) This computer is used for calculating statistics.

Which one is more suitable? In other words, are both of them give the same meaning? I am avoiding making contextual mistakes.

My problem is that I have read a sentence and I thought it should be corrected:

Actual sentence:

Bivariate linear regression is used to measure the degree of linear relationship between two variables.

After correction (not sure if it is really required):

Bivariate linear regression is used for measuring the degree of linear relationship between two variables.

I think (b) should be.

Answer

Al of your sentences are correct.

Note that in your (a) and (b) sentences, 'The computer is used' is the passive of 'X uses the computer'. It has nothing at al to do with the 'used to' for past habitual action.